eduOS/libkern/printf.c

/*-
 * Copyright (c) 1986, 1988, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
 */


/* 
 * eduOS's printf implementation is based on a implementation which was 
 * published at http://www.pagetable.com/?p=298. 
 * The authors built a full-featured standalone version of printf().  The
 * base code has been taken from FreeBSD (sys/kern/subr_prf.c) and is 
 * therefore BSD-licensed. Unnecessary functions have been removed and 
 * all typedefs required have been added.
 */

#include <eduos/string.h>

#define __64BIT__

#ifdef __64BIT__
typedef unsigned long long uintmax_t;
typedef long long intmax_t;
#else
typedef unsigned int uintmax_t;
typedef int intmax_t;
#endif
typedef unsigned char u_char;
typedef unsigned int u_int;
typedef unsigned long u_long;
typedef unsigned short u_short;
typedef unsigned long long u_quad_t;
typedef long long quad_t;
typedef unsigned long uintptr_t;
#define NBBY    8		/* number of bits in a byte */
char const hex2ascii_data[] = "0123456789abcdefghijklmnopqrstuvwxyz";
#define hex2ascii(hex)  (hex2ascii_data[hex])
#define va_list __builtin_va_list
#define va_start __builtin_va_start
#define va_arg __builtin_va_arg
#define va_end __builtin_va_end
#define toupper(c)      ((c) - 0x20 * (((c) >= 'a') && ((c) <= 'z')))

/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
#define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)

/*
 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
 * order; return an optional length and a pointer to the last character
 * written in the buffer (i.e., the first character of the string).
 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
 */
static char *ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
{
	char *p, c;

	p = nbuf;
	*p = '\0';
	do {
		c = hex2ascii(num % base);
		*++p = upper ? toupper(c) : c;
	} while (num /= base);
	if (lenp)
		*lenp = p - nbuf;
	return (p);
}

/*
 * Scaled down version of printf(3).
 *
 * Two additional formats:
 *
 * The format %b is supported to decode error registers.
 * Its usage is:
 *
 *	printf("reg=%b\n", regval, "*");
 *
 * where the output base is expressed as a control character, e.g.
 * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
 * the first of which gives the bit number to be inspected (origin 1), and
 * the next characters (up to a control character, i.e. a character <= 32),
 * give the name of the register.  Thus:
 *
 *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
 *
 * would produce output:
 *
 *	reg=3
 *
 * XXX:  %D  -- Hexdump, takes pointer and separator string:
 *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
 *		("%*D", len, ptr, " " -> XX XX XX XX ...
 */
int kvprintf(char const *fmt, void (*func) (int, void *), void *arg, int radix,
	     va_list ap)
{
#define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
	char nbuf[MAXNBUF];
	char *d;
	const char *p, *percent, *q;
	u_char *up;
	int ch, n;
	uintmax_t num;
	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
	int cflag, hflag, jflag, tflag, zflag;
	int dwidth, upper;
	char padc;
	int stop = 0, retval = 0;

	num = 0;
	if (!func)
		d = (char *)arg;
	else
		d = NULL;

	if (fmt == NULL)
		fmt = "(fmt null)\n";

	if (radix < 2 || radix > 36)
		radix = 10;

	for (;;) {
		padc = ' ';
		width = 0;
		while ((ch = (u_char) * fmt++) != '%' || stop) {
			if (ch == '\0')
				return (retval);
			PCHAR(ch);
		}
		percent = fmt - 1;
		qflag = 0;
		lflag = 0;
		ladjust = 0;
		sharpflag = 0;
		neg = 0;
		sign = 0;
		dot = 0;
		dwidth = 0;
		upper = 0;
		cflag = 0;
		hflag = 0;
		jflag = 0;
		tflag = 0;
		zflag = 0;
 reswitch:	switch (ch = (u_char) * fmt++) {
		case '.':
			dot = 1;
			goto reswitch;
		case '#':
			sharpflag = 1;
			goto reswitch;
		case '+':
			sign = 1;
			goto reswitch;
		case '-':
			ladjust = 1;
			goto reswitch;
		case '%':
			PCHAR(ch);
			break;
		case '*':
			if (!dot) {
				width = va_arg(ap, int);
				if (width < 0) {
					ladjust = !ladjust;
					width = -width;
				}
			} else {
				dwidth = va_arg(ap, int);
			}
			goto reswitch;
		case '0':
			if (!dot) {
				padc = '0';
				goto reswitch;
			}
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9':
			for (n = 0;; ++fmt) {
				n = n * 10 + ch - '0';
				ch = *fmt;
				if (ch < '0' || ch > '9')
					break;
			}
			if (dot)
				dwidth = n;
			else
				width = n;
			goto reswitch;
		case 'b':
			num = (u_int) va_arg(ap, int);
			p = va_arg(ap, char *);
			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
				PCHAR(*q--);

			if (num == 0)
				break;

			for (tmp = 0; *p;) {
				n = *p++;
				if (num & (1 << (n - 1))) {
					PCHAR(tmp ? ',' : '<');
					for (; (n = *p) > ' '; ++p)
						PCHAR(n);
					tmp = 1;
				} else
					for (; *p > ' '; ++p)
						continue;
			}
			if (tmp)
				PCHAR('>');
			break;
		case 'c':
			PCHAR(va_arg(ap, int));
			break;
		case 'D':
			up = va_arg(ap, u_char *);
			p = va_arg(ap, char *);
			if (!width)
				width = 16;
			while (width--) {
				PCHAR(hex2ascii(*up >> 4));
				PCHAR(hex2ascii(*up & 0x0f));
				up++;
				if (width)
					for (q = p; *q; q++)
						PCHAR(*q);
			}
			break;
		case 'd':
		case 'i':
			base = 10;
			sign = 1;
			goto handle_sign;
		case 'h':
			if (hflag) {
				hflag = 0;
				cflag = 1;
			} else
				hflag = 1;
			goto reswitch;
		case 'j':
			jflag = 1;
			goto reswitch;
		case 'l':
			if (lflag) {
				lflag = 0;
				qflag = 1;
			} else
				lflag = 1;
			goto reswitch;
		case 'n':
			if (jflag)
				*(va_arg(ap, intmax_t *)) = retval;
			else if (qflag)
				*(va_arg(ap, quad_t *)) = retval;
			else if (lflag)
				*(va_arg(ap, long *)) = retval;
			else if (zflag)
				*(va_arg(ap, size_t *)) = retval;
			else if (hflag)
				*(va_arg(ap, short *)) = retval;
			else if (cflag)
				*(va_arg(ap, char *)) = retval;
			else
				*(va_arg(ap, int *)) = retval;
			break;
		case 'o':
			base = 8;
			goto handle_nosign;
		case 'p':
			base = 16;
			sharpflag = (width == 0);
			sign = 0;
			num = (uintptr_t) va_arg(ap, void *);
			goto number;
		case 'q':
			qflag = 1;
			goto reswitch;
		case 'r':
			base = radix;
			if (sign)
				goto handle_sign;
			goto handle_nosign;
		case 's':
			p = va_arg(ap, char *);
			if (p == NULL)
				p = "(null)";
			if (!dot)
				n = strlen(p);
			else
				for (n = 0; n < dwidth && p[n]; n++)
					continue;

			width -= n;

			if (!ladjust && width > 0)
				while (width--)
					PCHAR(padc);
			while (n--)
				PCHAR(*p++);
			if (ladjust && width > 0)
				while (width--)
					PCHAR(padc);
			break;
		case 't':
			tflag = 1;
			goto reswitch;
		case 'u':
			base = 10;
			goto handle_nosign;
		case 'X':
			upper = 1;
		case 'x':
			base = 16;
			goto handle_nosign;
		case 'y':
			base = 16;
			sign = 1;
			goto handle_sign;
		case 'z':
			zflag = 1;
			goto reswitch;
 handle_nosign:
			sign = 0;
			if (jflag)
				num = va_arg(ap, uintmax_t);
			else if (qflag)
				num = va_arg(ap, u_quad_t);
			else if (tflag)
				num = va_arg(ap, ptrdiff_t);
			else if (lflag)
				num = va_arg(ap, u_long);
			else if (zflag)
				num = va_arg(ap, size_t);
			else if (hflag)
				num = (u_short) va_arg(ap, int);
			else if (cflag)
				num = (u_char) va_arg(ap, int);
			else
				num = va_arg(ap, u_int);
			goto number;
 handle_sign:
			if (jflag)
				num = va_arg(ap, intmax_t);
			else if (qflag)
				num = va_arg(ap, quad_t);
			else if (tflag)
				num = va_arg(ap, ptrdiff_t);
			else if (lflag)
				num = va_arg(ap, long);
			else if (zflag)
				num = va_arg(ap, ssize_t);
			else if (hflag)
				num = (short)va_arg(ap, int);
			else if (cflag)
				num = (char)va_arg(ap, int);
			else
				num = va_arg(ap, int);
 number:
			if (sign && (intmax_t) num < 0) {
				neg = 1;
				num = -(intmax_t) num;
			}
			p = ksprintn(nbuf, num, base, &tmp, upper);
			if (sharpflag && num != 0) {
				if (base == 8)
					tmp++;
				else if (base == 16)
					tmp += 2;
			}
			if (neg)
				tmp++;

			if (!ladjust && padc != '0' && width
			    && (width -= tmp) > 0)
				while (width--)
					PCHAR(padc);
			if (neg)
				PCHAR('-');
			if (sharpflag && num != 0) {
				if (base == 8) {
					PCHAR('0');
				} else if (base == 16) {
					PCHAR('0');
					PCHAR('x');
				}
			}
			if (!ladjust && width && (width -= tmp) > 0)
				while (width--)
					PCHAR(padc);

			while (*p)
				PCHAR(*p--);

			if (ladjust && width && (width -= tmp) > 0)
				while (width--)
					PCHAR(padc);

			break;
		default:
			while (percent < fmt)
				PCHAR(*percent++);
			/*
			 * Since we ignore a formatting argument it is no
			 * longer safe to obey the remaining formatting
			 * arguments as the arguments will no longer match
			 * the format specs.
			 */
			stop = 1;
			break;
		}
	}
#undef PCHAR
}

/*
 * Print directly a character on the screen
 */
extern int kputchar(int);

/*
 * A wrapper function for kputchar because
 * kvprintf needs an output function, which possesses two arguments.
 * The first arguments defines the output character, the second could be used to pass
 * additional arguments. In the case of kputchar is no additional argument needed.
 */
static void _putchar(int c, void *arg)
{
	kputchar(c);
}

int kprintf(const char *fmt, ...)
{
	int ret;

	/* http://www.pagetable.com/?p=298 */
	va_list ap;

	va_start(ap, fmt);
	ret = kvprintf(fmt, 
		       _putchar,	/* output function */
		       NULL,	 	/* additional argument for the output function */
		       10, ap);
	va_end(ap);

	return ret;
}